This invention relates to thyratrons and more particularly to cold cathode thyratrons.
Conventionally, thyratrons include an anode, a cathode and one or more control grids located between them, contained within an envelope which also contains a gas filling, typically of hydrogen. A thyratron may typically also have a screen grid between the anode and the control grid or grids. The cathode in a conventional thyratron is generally a thermionic cathode in which electrons are emitted by a thermionic material when it reaches a required temperature, a cathode heater being included to achieve this. Some disadvantages arise from such an arrangement. A supply must be provided for the cathode heater, and it takes the thermionic material a relatively long time (minutes) to reach the temperature required for satisfactory operation of the thyratron.